Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds

Definitions

• the invention relates to a thermoplastic masterbatch for the production of plastic films with antiblocking properties.
• thermoplastics or plastic mixtures In the manufacture of e.g. B. tubular films made of thermoplastics or plastic mixtures, a lard of these thermoplastic mixtures is extruded through an annular slot die to form a tube, which is inflated, cooled, laid flat and wound up.
• diatomaceous earth commercially available silica and silica gels whose particle size distribution lies within this range can be used as Si0 2 -containing substances.
• JP-A-7 515 744 it is known to produce axially stretched polypropylene films with good transparency and satisfactory antiblocking properties by adding mineral zeolites to the polypropylene in amounts of 0.05 to 0.5% by weight directly and without batch production will.
• JP-A-7 423 245 it is known to use compositions consisting of polypropylene or copolymers of propylene with other ⁇ -olefins, zeolite powder with an average grain size below 20 microns in an amount of 0.01 to 5.0% by weight to add.
• thermoplastic mixtures have the disadvantage that they contain substances as antiblocking agents which have to be made almost water-free before they are kneaded in complex drying processes, since the presence of moisture in the thermoplastic mixture causes the formation of bubbles at the given processing temperatures.
• the object of the invention is to find a thermoplastic masterbatch with an inorganic filler which has a good antiblocking effect in a plastic film and whose inorganic filler component does not have to be dried to an anhydrous state.
• the invention relates to a thermoplastic masterbatch for the production of plastic films with antiblocking properties based on polyethylene, which is characterized in that it comprises 20 to 60% by weight of a synthetic, powdery zeolite of type A, type Y, type X , of the type P and / or of the type hydroxysodalite, which has a particle size of 0.5 to 20 micrometers and a water content of 15 to 27% by weight.
• thermoplastic masterbatches according to the invention can be processed into films which contain 0.05 to 2% by weight, in particular 0.05 to 1.0% by weight, of a powdery zeolite.
• the thermoplastic masterbatches can contain a powdered zeolite, the particles of which have a particle size of 0.5 to 10 micrometers.
• B. the Coulter Counter method can be used. This particle size can be achieved by the precipitation processes of the zeolite synthesis and / or subsequently by grinding.
• zeolite corresponds to the description according to D. W. Breck, "Zeoliteolekulare sievesr", Wiley Interscience 1974, pages 133 to 180.
• the zeolites used have a water content of 15 to 27% by weight.
• M is a metal cation, such as. B. sodium or potassium cation
• n is its valency
• y is a value up to 5.
• the thermoplastic masterbatches can preferably contain a zeolite of type A, which is prepared by processes according to DE-AS-2 333 068, DE-AS-2 447 021, DE-AS-2 517 218, DE-OS-2 651 485, DE- OS-2 651 446, DE-OS-2 651 436, DE-OS-2 651 419, DE-OS-2 651 420 and / or DE-OS-2 651 437 is produced.
• the zeolite A used can also be prepared by other known processes, e.g. B. according to DE-PS-1 038 017 or DE-AS-1 667 520.
• the zeolite A used can preferably have the following physico-chemical data: Grain distribution (Coulter counter): Furthermore, the thermoplastic masterbatches according to the invention can, as powdered zeolites, be a type Y zeolite with the general formula contain, where M is a metal cation, such as. B. sodium or potassium cation, n its value, x is a value greater than 3 and y is a value up to 9.
• This zeolitic molecular sieve powder can be prepared, for example, according to DE-AS-1 099 929, DE-AS-1 203 239 or DE-AS-1 253 055.
• thermoplastic masterbatches according to the invention can, as powdered zeolites, be a type X zeolite with the general formula contain, where M is a metal cation, e.g. B. sodium or potassium cation, n is its valency and y is a value up to 8.
• M is a metal cation, e.g. B. sodium or potassium cation
• n is its valency
• y is a value up to 8.
• This powdered zeolite can be produced according to DE-PS-1 038 016, DE-PS-1 138 383 or DE-OS-2 028 163.
• thermoplastic masterbatches according to the invention can preferably contain a type P zeolite as powdered zeolites.
• the designation zeolite P is synonymous with the designation of synthetic phillipsite and zeolite B.
• the zeolite P can be produced by the process according to FR-PS-1 213 528 (Bayer AG).
• thermoplastic masterbatches according to the invention can also be used as powdered zeolites hydroxysodalite with the general formula contain.
• Hydroxysodalite can be prepared, for example, from zeolite A by boiling in aqueous sodium hydroxide solution (cf. DW Breck "Zeolite molecular sieves", page 275 [1974] Wiley Interscience Publication).
• the thermoplastic masterbatches according to the invention can contain a mixture of the indicated zeolites. These masterbatches can be produced by mixing the pure zeolites as well as by direct synthesis. Masterbatches which can be produced directly can be mixtures of zeolites A and P, zeolites A and X, zeolites A and hydroxysodalite, zeolites P and X or zeolites P and Y. In a preferred embodiment, the thermoplastic masterbatches can contain a mixture of zeolite X and zeolite P in a ratio of 80 to 5 to 20 to 95.
• Such a mixture can be produced, for example, according to DE-OS-2 028 153, page 15, table 3, example 3 by means of a precipitation process.
• thermoplastic masterbatches of the present invention can be polyethylene with the following. Key data include:
• mixtures of polyethylenes can also be used in the masterbatches according to the invention, and polyethylene waxes can also be used in such mixtures.
• the polyethylenes can contain conventional additives that are normally incorporated to make the thermoplastics resistant to heat, atmospheric oxygen and light interference.
• Stabilizers of this type include carbon black, 2,2-thio-bis (4-methyl-6-tert-butylphenoi), dilauryl thiodipriopionate as well as various other known amine and phenol stabilizers.
• the fillers suitable for the invention have a particle size of 0.5 to 20 micrometers.
• the particle size of the filler should preferably be 0.5 to 10 micrometers. This particle size leads to speck-free surfaces with good antiblocking behavior.
• the masterbatches according to the invention can also contain other conventional additives, such as lubricants and dyes.
• Plastic films can be produced from the thermoplastic masterbatches according to the invention by mixing the individual constituents at a suitable temperature in a suitable mixing device, for example in an internal mixer of the "Banbury” type.
• the thermoplastic masterbach thus obtained can then be mixed by further addition of Plastic to a content of 0.05 to 1 wt .-% of powdered zeolites optionally diluted in the same mixing device and z. B. be blown by means of an extruder-blowing device at a suitable temperature into thin films.
• the masterbatches according to the invention have the advantage that they contain a powdered zeolite as an antiblocking agent, which despite a water content of 15 to 27% by weight in the production of the thermoplastic mixture, even at temperatures of more than 170 ° C., does not cause any disruptive gas bubbles due to water vapor being released forms in the thermoplastic mixture.
• This property makes zeolites superior to silica gels and precipitated silicas, the physically bound water of which escapes at 105 ° C and which must therefore be dried to a very low water content beforehand and protected against the ingress of atmospheric moisture by special packaging. Compared to diatomaceous earths, this superiority only concerns the fact of predrying and less the aspect of special packaging.
• thermoplastic masterbatches according to the invention can also have a content of up to 50% by weight of the zeolitic antiblocking agent, as a result of which the space-time yield of the expensive kneader system can be better exploited and the manufacturing process of the antiblocking agent masterbatches can be made considerably more economical.
• the products of the prior art z. B. like silica gels and precipitated silicas due to their higher thickening effect in the thermoplastic mixture up to a maximum of 25-30% by weight, diatomaceous earths can at least achieve degrees of filling of up to 50% by weight.
• the mixtures according to the invention are clearly superior to the mixtures which contain silica gels and precipitated silicas and those which contain diatomaceous earths.
• the dispersibility of the same in the thermoplastic mixture plays a crucial role.
• the excellent dispersibility of the zeolitic antiblocking agents according to the invention not only is the kneading time of the thermoplastic masterbatch considerably shortened and thus the space-time yield of the kneading process is increased, but also the risk that the antiblocking agent aggregates are broken down under the action of shear forces of the dispersing device , which leads to a shift in the average particle size, which is accompanied by a decrease in the antiblocking effect.
• Powdered zeolites develop a very low abrasiveness in the mixture compared to the products of the prior art, as a result of which the kneader is protected during the production of the thermoplastic mixtures. This is particularly true when compared to diatomaceous earths, which have a relatively high abrasiveness as a result of their quartz content.
• the zeolite A which can be used according to the invention has been classified as toxicologically harmless in extensive inhalation toxicological and toxicological studies. Although this statement also applies to silica gels and precipitated silicas, in contrast, for the diatomaceous earths containing up to a few percent, stricter protective measures must be observed for the operating personnel during processing (MAK value at 4 mg / Nm 3 ).
• the fine particle size and particle size distribution of the zeolites used in accordance with the invention ensure not only good dispersibility but also freedom from specks and high quality of the surface of the films. No product of the prior art achieves such a good surface structure.
• a zeolitic molecular sieve powder When processed in a kneader, a zeolitic molecular sieve powder is less prone to dusting due to its high water content of 15 to 27% by weight, which means that the working conditions of the environmental protection regulations can be easily complied with.
• thermoplastic masterbatches according to the invention and the foils made therefrom absorb almost no moisture from the air.
• the melt index MFI provides information about the change in the rheological behavior of the polymer melts caused by the antiblocking agents.
• the measurement is carried out according to DIN 53 735. A temperature of 190 ° C and a load of 5 kp was selected as the test condition.
• the aim is that the melt index of the concentrate is of the same order of magnitude or higher than the melt index of the LDPE used for the film production (in the present example 11 g / 10 min with an increased test load of 5 kp instead of 2.16 kp).
• Blocking means the property of two evenly touching foils that can only be separated again with the application of more or less great force.
• the measurement can be carried out in a peeling test by measuring the force required to pull apart.
• a further measure of the blocking properties is the coefficient of sliding friction. Strictly speaking, this size is a measure of the movability of two touching foils, but it provides usable dimensions compared to manual separation tests.
• the peeling test is carried out in accordance with ASTM-D 1893.
• pairs of foils measuring 250 x 120 mm are put together, loaded with 20 g / cm 2 and stored at 60 ° C. for 24 hours.
• the films are then separated by pulling them over a rod that slides between the contacting surfaces. The force required for this is called the blocking force and is measured in grams.
• the coefficient of sliding friction is measured based on DIN 53 375.
• a film strip of 200 x 300 mm is stretched onto a glass plate, another film piece of 50 x 50 mm is placed, loaded and pulled off at a feed rate of 100 mm / min.
• a metal cylinder with a pressure surface of 10 cm 2 and a weight of 200 g serves as the loading weight.
• the coefficient of friction results from the division of tensile force / contact force.
• the zeolites A and P are compared with the precipitated silica and the silica gel Syloidlb 244.
• concentrates are first made with 20% of the products mentioned. The concentration was reduced in consideration of the comparative products.
• LDPE LUPOLEN E 2430 H is used instead of LUPOLEN® 3010 K for film production.
• the measured values listed in Table 2 show that very good antiblocking properties are also obtained with this LDPE by using the zeolites.
• the numbers for the melt indices of the concentrates also show the greatly improved flow behavior compared to the precipitated silica and especially the Syloid ® 244 silica gel.
• Table 4 clearly shows the superiority of zeolite A over the comparison products.
• the silica gel Syloid 0 385 used in the examples has the following physico-chemical characteristics:
• the silica gel Syloid ° 244 used in the examples has the following physico-chemical characteristics:
• the zeolite A used in the examples is produced according to DE-OS-2 651 436.
• the zeolite X used in the examples is produced in accordance with DE-PS-1 038 016 and then ground in a pin mill.
• the zeolite Y used in the examples is produced according to DE-PS-1 098 929 and then ground in a pin mill.
• the zeolite P used in the examples is produced according to FR-PS-1 213 628.
• the hydroxysodalite used in the examples is prepared from a zeolite A according to DE-OS-2 447 021 by boiling for three days with NaOH (20%). The product is filtered off, washed, dried and ground on a pin mill.
• the grain size distribution of the zeolites used, determined using a Coulter counter, is shown in FIGS. 1 to 5.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Laminated Bodies (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)

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• 1978
  • 1978-08-01 DE DE2833675A patent/DE2833675C2/de not_active Expired
• 1979
  • 1979-06-05 ES ES481282A patent/ES481282A1/es not_active Expired
  • 1979-06-05 FR FR7914353A patent/FR2432533A1/fr active Granted
  • 1979-06-07 NL NLAANVRAGE7904492,A patent/NL177221C/nl not_active IP Right Cessation
  • 1979-06-28 IT IT68371/79A patent/IT1119306B/it active
  • 1979-07-13 MX MX798185U patent/MX6402E/es unknown
  • 1979-07-23 EP EP79102596A patent/EP0007608B2/de not_active Expired
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  • 1979-07-23 AT AT79102596T patent/ATE1821T1/de active
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  • 1979-07-30 BE BE6/46903A patent/BE877979A/fr not_active IP Right Cessation
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  • 1979-07-31 CH CH706779A patent/CH639984A5/de not_active IP Right Cessation
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